Name: protein interaction capture methods in cells
Uploaded: 2023-04-30T06:31:42.000Z
Duration: 8 min 8 s
Channel: JoVE

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HS-PS1-5.

co-immunoprecipitation-and-pull-down-assays

Co-Immunoprecipitation and Pull-Down Assays

Co-immunoprecipitation (CoIP) and pull-down assays are closely related methods to identify stable protein-protein interactions. These methods are related to immunoprecipitation, a method for separating a target protein bound to an antibody from unbound proteins. In CoIP, an antibody-bound protein is itself bound to another protein that does not bind with the antibody, this is followed by a separation process that preserves the protein-protein complex. The difference in pull-down assays is that affinity-tagged bait proteins replace antibodies, and affinity chromatography is used to isolate protein-protein complexes.
This video explains CoIP, pull-down assays, and their implementation in the laboratory. A step-by-step protocol for each technique is covered, including the reagents, apparatus, and instruments used to purify and analyze bound proteins. Additionally, the applications section of this video describes a procedure to study how myxovirus proteins inhibit influenza nucleoprotein, an investigation into the role of calcium ions in calmodulin via a pull-down assay, and a modified pull-down assay for characterizing transient protein interactions.

co-immunoprecipitation and pull-down assays

Co-immunoprecipitation (CoIP) and pull-down assays are closely related methods to identify stable protein-protein interactions. These methods are related to immunoprecipitation, a method for separating a target protein bound to an antibody from unbound proteins. In CoIP, an antibody-bound protein is itself bound to another protein that does not bind with the antibody, this is followed by a separation process that preserves the protein-protein complex. The difference in pull-down assays is that affinity-tagged bait proteins replace antibodies, and affinity chromatography is used to isolate protein-protein complexes.
This video explains CoIP, pull-down assays, and their implementation in the laboratory. A step-by-step protocol for each technique is covered, including the reagents, apparatus, and instruments used to purify and analyze bound proteins. Additionally, the applications section of this video describes a procedure to study how myxovirus proteins inhibit influenza nucleoprotein, an investigation into the role of calcium ions in calmodulin via a pull-down assay, and a modified pull-down assay for characterizing transient protein interactions.
<div class="chapter_text" id="script_0">
Protein-protein interactions play a significant role in a wide variety of biological functions. The majority of protein-protein interactions and their biological effects have yet to be identified. Co-immunoprecipitation, or CoIP, and pull-down assays are two closely related methods for the identification of stable protein-protein interactions. This video will cover the principles of the two assays, their general laboratory procedures, and applications of these techniques.
</div>
<div class="chapter_text" id="script_1">
CoIP and pull-down assays are variants of immunoprecipitation, a method for selectively isolating a protein species from a complex solution. In an immunoprecipitation experiment, an antibody specific to a target protein is allowed to form an immune complex with that target in the sample. The complex is then captured on a solid support, typically protein A bound to a sepharose bead. Any proteins not captured are removed by centrifugation steps. The protein is then released from the antibody and solid support by boiling in reducing SDS-PAGE sample-loading buffer.
Co-immunoprecipitation is conducted in the same manner, except that intact protein complexes are captured onto the solid support. The antibody binds to the target protein, which, in turn, is bound to another protein that is not targeted by the antibody. As in immunoprecipitation, the protein complex is released from the antibody and solid support by boiling in reducing SDS-PAGE sample loading buffer.
Pull-down assays are similar to co-immunoprecipitation, differing only in the use of a &#34;bait&#34; protein, as opposed to an antibody. Through molecular biology techniques, this bait protein is engineered with an affinity tag, such as a series of histidine residues. These affinity tags are described in &#34;Chromatography-based Biomolecule Separations.&#34; The protein is then captured on an immobilized affinity ligand specific for the tag. The captured protein is then incubated with a sample that contains proteins that form complexes with the &#34;bait&#34;. The protein complex is released from the affinity support by washing with a solution containing a competitive analyte specific for the tag on the &#34;bait&#34; protein. Pull-down assays are useful for confirming protein interactions predicted by co-immunoprecipitation, and for discovering unknown protein interactions.
Now that the principles of co-immunoprecipitation and pull-down assays have been discussed, let&#39;s look at their laboratory procedures.
</div>
<div class="chapter_text" id="script_2">
First let&#39;s discuss co-immunoprecipitation. To a series of microfuge tubes, the following is added: PBS buffer, and a 50% solution of protein A-sepharose, a resin-protein complex that binds to the antibody. The microfuge tubes are rotated to ensure proper distribution, and then the resin is washed with additional PBS buffer. Cell lysate, containing the desired protein, and 2 &#956;g of antibody are added to the microfuge tubes, and the mixture is rotated for 1 h at 4 &#176;C. The beads are pelleted by centrifugation, the supernatant is discarded, and the beads re-washed three times with buffer to remove non-bound protein. The beads containing the antibody-protein complex are in reducing SDS-PAGE sample-loading buffer, for removal of the complex from the antibody and for analysis by SDS-PAGE and immunoblotting.
</div>
<div class="chapter_text" id="script_3">
Now we will discuss the procedure for pull-down assays: The &#34;bait&#34; protein is expressed in a plasmid with the appropriate affinity tag. After reaching log-phase growth, the cells are lysed, and then centrifuged. Suspended streptavidin-sepharose beads, which capture biotin-tagged &#34;bait&#34; protein, are pipetted into a microfuge tube. The beads are then centrifuged and the supernatant carefully removed by aspiration. The beads are then washed with buffer, centrifuged, and the supernatant removed.
Cells containing the putative &#34;prey&#34; protein, which has an affinity for the &#34;bait&#34; protein, are harvested by centrifugation. The supernatant is then added to the microfuge tube containing the resin, and incubated at 4 &#176;C for 3 h on a shaker. The resin is then centrifuged, the supernatant removed, and the resin washed to remove non-bound protein. Elution buffer is added to the resin, and the mixture is incubated at room temperature for 30 min on a shaker. The resin is then centrifuged, and the supernatant containing the desired complex is analyzed by immunoblotting.
</div>
<div class="chapter_text" id="script_4">
Now that we&#39;ve reviewed the procedures, let&#39;s look at some of the useful applications of co-immunoprecipitation and pull-down assays.
Co-immunoprecipitation can be useful in better understanding of enzymes&#39; mechanism of action. Myxovirus-, or Mx-, resistance proteins inhibit a wide range of viruses, including influenza A, for which the mechanism is poorly understood. Co-immunoprecipitation was used to study the interaction between mouse Mx1 protein and influenza nucleoprotein.
Pull-down assays have proven useful in studying the effects of second messengers, which are proteins that communicate a signal from the cellular environment. They are a component of a signaling pathway where multiple proteins interact in response to environmental cues. Calcium ions act as secondary messengers by binding to calmodulin, which, in turn, binds to a wide variety of proteins, mediating many types of biological responses. Without the calcium, the protein can&#39;t bind to the calmodulin. A pull-down assay was conducted to test the ability of proteins to bind to calmodulin in the presence or absence of calcium ions.
Co-immunoprecipitation and pull-down assays are generally used for analyzing stable or strong protein interactions, but not transient ones. A recent development in pull-down assays, the HaloTag, has simplified the study of transient protein interactions; HaloTag is a genetically-encoded protein fusion tag, fused to the protein of interest, capable of chemically reacting with a haloalkane solid support. If functional analysis is desired, the protein complex, minus the tag, in its entirety could then be isolated by incubating with tobacco etch virus protease.
</div>
<div class="chapter_text" id="script_5">
You&#39;ve just watched JoVE&#39;s video on co-immunoprecipitation and pull-down assays. This video described the principles of the two methods, the general laboratory procedures, and some of their applications.
Thanks for watching!
</div>

Co-immunoprecipitation (CoIP) and pull-down assays are closely related methods to identify stable protein-protein interactions. These methods are related ...

Protein-protein interactions play a significant role in a wide variety of biological functions. The majority of protein-protein interactions and their biological effects have yet to be identified. Co-immunoprecipitation, or CoIP, and pull-down assays are two closely related methods for the identification of stable protein-protein interactions. This video will cover the principles of the two assays, their general laboratory procedures, and applications of these techniques.CoIP and pull-down assays are variants of immunoprecipitation, a method for selectively isolating a protein species from a complex solution. In an immunoprecipitation experiment, an antibody specific to a target protein is allowed to form an immune complex with that target in the sample. The complex is then captured on a solid support, typically protein A bound to a sepharose bead. Any proteins not captured are removed by centrifugation steps. The protein is then released from the antibody and solid support by boiling in reducing SDS-PAGE sample-loading buffer.Co-immunoprecipitation is conducted in the same manner, except that intact protein complexes are captured onto the solid support. The antibody binds to the target protein, which, in turn, is bound to another protein that is not targeted by the antibody. As in immunoprecipitation, the protein complex is released from the antibody and solid support by boiling in reducing SDS-PAGE sample loading buffer.Pull-down assays are similar to co-immunoprecipitation, differing only in the use of a "bait" protein, as opposed to an antibody. Through molecular biology techniques, this bait protein is engineered with an affinity tag, such as a series of histidine residues. These affinity tags are described in "Chromatography-based Biomolecule Separations." The protein is then captured on an immobilized affinity ligand specific for the tag. The captured protein is then incubated with a sample that contains proteins that form complexes with the "bait". The protein complex is released from the affinity support by washing with a solution containing a competitive analyte specific for the tag on the "bait" protein. Pull-down assays are useful for confirming protein interactions predicted by co-immunoprecipitation, and for discovering unknown protein interactions.Now that the principles of co-immunoprecipitation and pull-down assays have been discussed, let's look at their laboratory procedures.First let's discuss co-immunoprecipitation. To a series of microfuge tubes, the following is added: PBS buffer, and a 50% solution of protein A-sepharose, a resin-protein complex that binds to the antibody. The microfuge tubes are rotated to ensure proper distribution, and then the resin is washed with additional PBS buffer. Cell lysate, containing the desired protein, and 2 ?g of antibody are added to the microfuge tubes, and the mixture is rotated for 1 h at 4 ?C. The beads are pelleted by centrifugation, the supernatant is discarded, and the beads re-washed three times with buffer to remove non-bound protein. The beads containing the antibody-protein complex are in reducing SDS-PAGE sample-loading buffer, for removal of the complex from the antibody and for analysis by SDS-PAGE and immunoblotting.Now we will discuss the procedure for pull-down assays: The "bait" protein is expressed in a plasmid with the appropriate affinity tag. After reaching log-phase growth, the cells are lysed, and then centrifuged. Suspended streptavidin-sepharose beads, which capture biotin-tagged "bait" protein, are pipetted into a microfuge tube. The beads are then centrifuged and the supernatant carefully removed by aspiration. The beads are then washed with buffer, centrifuged, and the supernatant removed.Cells containing the putative "prey" protein, which has an affinity for the "bait" protein, are harvested by centrifugation. The supernatant is then added to the microfuge tube containing the resin, and incubated at 4 ?C for 3 h on a shaker. The resin is then centrifuged, the supernatant removed, and the resin washed to remove non-bound protein. Elution buffer is added to the resin, and the mixture is incubated at room temperature for 30 min on a shaker. The resin is then centrifuged, and the supernatant containing the desired complex is analyzed by immunoblotting.Now that we've reviewed the procedures, let's look at some of the useful applications of co-immunoprecipitation and pull-down assays.Co-immunoprecipitation can be useful in better understanding of enzymes' mechanism of action. Myxovirus-, or Mx-, resistance proteins inhibit a wide range of viruses, including influenza A, for which the mechanism is poorly understood. Co-immunoprecipitation was used to study the interaction between mouse Mx1 protein and influenza nucleoprotein.Pull-down assays have proven useful in studying the effects of second messengers, which are proteins that communicate a signal from the cellular environment. They are a component of a signaling pathway where multiple proteins interact in response to environmental cues. Calcium ions act as secondary messengers by binding to calmodulin, which, in turn, binds to a wide variety of proteins, mediating many types of biological responses. Without the calcium, the protein can't bind to the calmodulin. A pull-down assay was conducted to test the ability of proteins to bind to calmodulin in the presence or absence of calcium ions.Co-immunoprecipitation and pull-down assays are generally used for analyzing stable or strong protein interactions, but not transient ones. A recent development in pull-down assays, the HaloTag, has simplified the study of transient protein interactions; HaloTag is a genetically-encoded protein fusion tag, fused to the protein of interest, capable of chemically reacting with a haloalkane solid support. If functional analysis is desired, the protein complex, minus the tag, in its entirety could then be isolated by incubating with tobacco etch virus protease.You've just watched JoVE's video on co-immunoprecipitation and pull-down assays. This video described the principles of the two methods, the general laboratory procedures, and some of their applications.Thanks for watching!

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Biochemistry

protein interaction capture methods in cells

Co-immunoprecipitation and pull-down assays are laboratory methods used to capture stable protein-protein interactions. Protein-protein interactions help control many biological functions, but many of them have not yet been identified. These assays are related to immunoprecipitation, which isolates a target protein from a mixed sample using an antibody.

In co-immunoprecipitation, or CoIP, an antibody binds the target protein, and that protein is already attached to another protein that the antibody does not recognize. The intact protein complex is collected on a solid support, such as protein A on sepharose beads, so the interaction is preserved during separation. In pull-down assays, the bait protein is tagged instead of using an antibody. The tagged bait is captured by affinity chromatography and used to isolate the proteins that bind to it.

The CoIP procedure begins with PBS buffer and protein A-sepharose in microfuge tubes. The tubes are rotated, washed, and then mixed with cell lysate and about 2 micrograms of antibody. After 1 hour at 4 degrees Celsius, the beads are centrifuged, washed three times, and placed in reducing SDS-PAGE sample-loading buffer. The released proteins are then analyzed by SDS-PAGE and immunoblotting.

The pull-down procedure uses a bait protein expressed with an affinity tag, such as a series of histidine residues or a biotin tag. After the cells reach log-phase growth, they are lysed and centrifuged. Streptavidin-sepharose beads can capture the biotin-tagged bait, and the beads are then washed before the putative prey protein is added. The mixture is incubated at 4 degrees Celsius for 3 hours on a shaker, washed again, and eluted with buffer. The final complex is analyzed by immunoblotting.

These methods are useful for confirming predicted protein interactions and for finding unknown ones. CoIP has been used to study how mouse Mx1 protein interacts with influenza nucleoprotein, which helps explain the action of myxovirus resistance proteins against influenza A. Pull-down assays have also been used to test how calcium ions affect calmodulin binding, since calmodulin binds many proteins only when calcium is present. For transient protein interactions, a modified pull-down approach using HaloTag can help, and tobacco etch virus protease can remove the tag if functional analysis is needed.

Protein Interaction Capture Methods in Cells

protein-interaction-capture-methods-in-cells

dialysis: diffusion based separation

Dialysis for Buffer Exchange in Biochemistry

Dialysis is a common biochemistry technique for buffer exchange and desalting. It separates molecules by diffusion through a semipermeable membrane, which lets small molecules pass while holding larger biomolecules inside the sample. The membrane is the key part of the setup. Its pores create a molecular weight cutoff, so a membrane such as a 10 kDa membrane usually keeps molecules larger than 10 kilodaltons inside. This cutoff is not exact, because membranes have a range of pore sizes.

enzyme assays and kinetics

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How MALDI-TOF Reads Biomolecules

MALDI-TOF mass spectrometry reads biomolecules by using a laser, a matrix, and a time-of-flight analyzer. MALDI, or matrix-assisted laser desorption ionization, helps fragile molecules keep their structure while they are moved into the mass analyzer. The analyzer then separates compounds based on size and charge. In MALDI, the sample is mixed into a matrix, usually an organic compound with aromatic and conjugated double bonds. A laser pulse strikes the spot, and the matrix absorbs most of the...

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Tandem Mass Spectrometry for Biomolecule Analysis

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chromatography-based biomolecule purification methods

chromatography-based-biomolecule-purification-methods

Protein Purification with SEC and IMAC

Protein purification with size-exclusion chromatography and affinity chromatography helps isolate biomolecules from complex mixtures. These methods are common in biochemistry because purified samples are needed before a biomolecule’s properties and activity can be studied. The video focuses on the principles behind size-exclusion chromatography, affinity chromatography, and immobilized metal affinity chromatography, or IMAC. Size-exclusion chromatography, or SEC, separates molecules by size. A...

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Protein Mapping with 2D Gel Electrophoresis

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electrophoretic mobility shift assay (emsa)

electrophoretic-mobility-shift-assay-emsa

Detecting Protein-DNA Binding by EMSA

Electrophoretic mobility shift assay, or EMSA, is a biochemical method used to detect binding between proteins and nucleic acids. It is also called a gel shift assay. The test compares how a labeled nucleic acid moves through a gel before and after it binds a protein. EMSA is used to see whether a specific protein binds to a specific nucleic acid. First, the nucleic acid is labeled to make a probe. The transcript describes radioactive phosphorus-32 as a common label. The probe is then mixed...

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Sucrose gradient separation in an ultracentrifuge is a lab method for isolating cell parts and biomolecules. It uses differences in density to make particles sink or rise in a liquid. A high-speed ultracentrifuge speeds up this process so components can be separated without destroying them. The basic idea starts with a suspension, which is particles mixed in a liquid solvent. Particles that are denser than the solvent sediment, while less dense particles float. A rotor inside the...

Co-immunoprecipitation and pull-down assays are laboratory methods used to capture stable protein-protein interactions. Protein-protein interactions help control many biological functions, but many of them have not yet been identified. These assays are related to immunoprecipitation, which isolates a target protein from a mixed sample using an antibody. In co-immunoprecipitation, or CoIP, an antibody binds the target protein, and that protein is already attached to another protein that the...

reconstitution of membrane proteins

Membrane Proteins in Liposome Models

Membrane proteins can be moved into liposome models so their function can be studied outside a cell. Reconstitution means restoring an isolated biomolecule to a working form. For membrane proteins, that usually means placing a purified protein into an artificial lipid membrane. Cell membranes are made mainly of phospholipids and membrane proteins. The phospholipids form a bilayer with hydrophilic phosphate heads facing water and hydrophobic fatty acid tails facing inward. Some membrane...

f&#246;rster resonance energy transfer (fret)

FRET as a Molecular Ruler in Cells

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SPR Biosensors for Tracking Binding Kinetics

Surface plasmon resonance, or SPR, is a way to track biomolecular binding on a label-free biosensor. It is used to measure molecular affinity, kinetics, specificity, and concentration. The method works with a thin metal layer on a prism, where changes in reflected light reveal interactions in real time. SPR sensors use a thin layer of a noble metal on the face of a prism. Light is reflected from the prism-metal interface into a photodetector. At one specific angle, called the surface plasmon...

biochemistry

This collection presents commonly used purification methods, such as affinity chromatography, as well as analytical methods, like MALDI-TOF. In addition, the videos showcase methods for assessing biomolecule interaction and function, such as co-immunoprecipitation and metabolic labeling.

Learn how CoIP and pull-down assays capture protein-protein interactions, from bead-based lab steps to examples with influenza proteins and calmodulin.

Protein Interaction Capture Methods in Cells | JoVE K12

Life Science

Structure and Function

HS-LS1-2.

matter-and-energy-in-organisms-and-ecosystems

Matter and Energy in Organisms and Ecosystems

HS-LS1-6.

Overview

Principles of Co-Immunoprecipitation and Pull-Down Assays

Protocol for Co-Immunoprecipitation

Protocol for Pull-Down Assays

Applications

Summary

The Periodic Table

As early chemists discovered more elements, they realized that various elements could be grouped by their similar chemical behaviors. One such grouping ...

Alkali Metals

Group 1 elements are soft and shiny metallic solids. They are malleable, ductile, and good conductors of heat and electricity. The melting points of the ...

Halogens

Group 17 elements, known as halogens, are nonmetals. At room temperature, fluorine and chlorine are gases, bromine is a liquid, and iodine a solid. ...

Noble Gases


The elements in group 18 are noble gases (helium, neon, argon, krypton, xenon, and radon). They earned the name &ldquo;noble&rdquo; because they were ...

Classifying Matter by State

Chemistry is the study of matter and the changes it undergoes. Matter is anything that has mass and occupies space. Matter is all around us; the air, ...

Classifying Matter by Composition

Matter: Pure Substances and Mixtures
According to its composition, the matter can be classified into two broad categories &mdash; pure substances and ...

physical-and-chemical-properties-of-matter

Physical and Chemical Properties of Matter

The characteristics that enable us to distinguish one substance from another are called properties.

Physical Properties of Matter

A physical property is ...

Types of Chemical Bonds

Chemical bonding theories were pioneered by American chemist Gilbert&#xA0;N. Lewis. He developed a model called the Lewis model to explain the type and ...

Lewis Symbols and the Octet Rule

Chemical bonds are complex interactions between two or more atoms or ions, which reduce the potential energy of the molecule. Gilbert N. Lewis developed a ...

Ionic Bonding and Electron Transfer

Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence ...

The Born-Haber Cycle

Lattice Energy&#xA0;

An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a ...

trends-in-lattice-energy-ion-size-and-charge

Trends in Lattice Energy: Ion Size and Charge

An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure ...

Covalent Bonding and Lewis Structures

Compared to ionic bonds, which results from the transfer of electrons between metallic and nonmetallic atoms, covalent bonds result from the mutual ...

Electronegativity

Whether a bond is nonpolar or polar covalent is determined by a property of the bonding atoms called electronegativity.&#xA0;

Electronegativity values of ...

Ionization Energy

The amount of energy required to remove the most loosely bound electron from a gaseous atom in its ground state is called its first ionization energy ...

bond-polarity-dipole-moment-and-percent-ionic-character

Bond Polarity, Dipole Moment, and Percent Ionic Character

Bond Polarity

The absolute value of the difference in electronegativity (&Delta;EN) of two bonded atoms provides a rough measure of the polarity to be ...

Electron Affinity

The electron affinity (EA) is the energy change for adding an electron to a gaseous atom to form an anion (negative ion).



This process can be either ...

lewis-structures-of-molecular-compounds-and-polyatomic-ions

Lewis Structures of Molecular Compounds and Polyatomic Ions

To draw Lewis structures for complicated molecules and molecular ions, it is helpful to follow a step-by-step procedure as outlined:


	Determine the ...

assembly-of-a-reflux-system-for-heated-chemical-reactions

Assembly of a Reflux System for Heated Chemical Reactions

Source: Laboratory of Dr. Philip Miller &#8212; Imperial College London
Many chemical experiments require elevated temperatures before any reaction is ...

Resonance

The Lewis structure of a nitrite anion (NO2&minus;) may actually be drawn in two different ways, distinguished by the locations of the N-O and N=O ...

conducting-reactions-below-room-temperature

Conducting Reactions Below Room Temperature

Source: Laboratory of Dr. Dana Lashley - College of William and Mary
Demonstration by: Matt Smith
When new bonds are formed in the course of a chemical ...

Formal Charges

In some cases, there are seemingly more than one valid Lewis structures for molecules and polyatomic ions. The concept of formal charges can be used to ...

Coordination Chemistry Complexes

Source: Laboratory of Dr. Neal Abrams &#8212; SUNY College of Environmental Science and Forestry
Transition metals are found everywhere from vitamin ...

Exceptions to the Octet Rule

Many covalent molecules have central atoms that do not have eight electrons in their Lewis structures. These molecules fall into three categories:


	...

determining-rate-laws-and-the-order-of-reaction

Determining Rate Laws and the Order of Reaction

Source: Laboratory of Dr. Neal Abrams &#8212; SUNY College of Environmental Science and Forestry
All chemical reactions have a specific rate defining the ...

Bond Energies and Bond Lengths

Stable molecules exist because covalent bonds hold the atoms together. The strength of a covalent bond is measured by the energy required to break it, ...

Determining the Empirical Formula

Source: Laboratory of Dr. Neal Abrams - SUNY College of Environmental Science and Forestry
Determining the chemical formula of a compound is at the heart ...

Bonding in Metals

Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Dr&#xFC;de called the ...

determining-the-solubility-rules-of-ionic-compounds

Determining the Solubility Rules of Ionic Compounds

Source: Laboratory of Dr. Neal Abrams &#8212; SUNY College of Environmental Science and Forestry
An ionic compound&#39;s solubility can be determined via ...

atomic-radii-and-effective-nuclear-charge

Atomic Radii and Effective Nuclear Charge

The elements in groups of the periodic table exhibit similar chemical behavior. This similarity occurs because the members of a group have the same number ...

Introduction to Catalysis

Source: Laboratory of Dr. Ryan Richards &#8212; Colorado School of Mines
Catalysis is among the most important fields of modern technology and presently ...

Ionic Radii

Ionic radius is the measure used to describe the size of an ion. A cation always has fewer electrons and the same number of protons as the parent atom; it ...

Introduction to Titration

Source: Laboratory of Dr. Yee Nee Tan &#8212; Agency for Science, Technology, and Research
Titration is a common technique used to quantitatively ...

Le Ch&#226;telier's Principle

Source: Laboratory of Dr. Lynne O&#39;Connell &#8212; Boston College
When the conditions of a system at equilibrium are altered, the system responds in ...

preparing-anhydrous-reagents-and-equipment

Preparing Anhydrous Reagents and Equipment

Source: Laboratory of Dr. Dana Lashley - College of William and Mary
Demonstrated by: Timothy Beck and Lucas Arney
Many reactions in organic chemistry are ...

Proton Exchange Membrane Fuel Cells

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
The United States consumes a large amount of energy &#8211; the current ...

Solutions and Concentrations

Source: Laboratory of Dr. Michael Evans &#8212; Georgia Institute of Technology
A solution is a homogeneous mixture containing some components in small ...

spectrophotometric-determination-of-an-equilibrium-constant

Spectrophotometric Determination of an Equilibrium Constant

Source: Laboratory of Dr. Michael Evans &#8212; Georgia Institute of Technology
The equilibrium constant, K, for a chemical system is the ratio of product ...

using-differential-scanning-calorimetry-to-measure-changes-in-enthalpy

Using Differential Scanning Calorimetry to Measure Changes in Enthalpy

Source: Laboratory of Dr. Terry Tritt &#8212; Clemson University
Differential Scanning Calorimetry (DSC) is a method of thermodynamic analysis based on ...

Schlenk Lines Transfer of Solvents

Source: Hsin-Chun Chiu and Tyler J. Morin, laboratory of Dr. Ian Tonks&#8212;University of Minnesota Twin Cities
Schlenk lines and high vacuum lines are ...

Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.

HS-PS1-2.

Chemical Equations

Chemical equations represent the identities and relative quantities of substances involved in a chemical reaction. The substances undergoing reaction are ...

Chemical Reactions in Aqueous Solutions

Chemical substances interact in many different ways. Certain chemical reactions exhibit common patterns of reactivity. Due to the vast number of chemical ...

Precipitation Reactions

In a precipitation reaction, aqueous solutions of soluble salts react to give an insoluble ionic compound &#x2013; the precipitate. The reaction occurs ...

Oxidation-Reduction Reactions

Oxidation&ndash;Reduction Reactions

Earth&rsquo;s atmosphere contains about 20% molecular oxygen, O2, a chemically reactive gas that plays an essential ...

Oxidation Numbers

In redox reactions, the transfer of electrons occurs between reacting species. Electron transfer is described by a hypothetical number called the ...

Acids, Bases and Neutralization Reactions

An acid-base reaction is one in which a hydrogen ion, H+, is transferred from one chemical species to another. Such reactions are of central importance to ...

Synthesis and Decomposition Reactions

Synthesis and decomposition are two types of redox reactions. Synthesis means to make something, whereas decomposition means to break something. The ...

Develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends upon the changes in total bond energy.

HS-PS1-4.

Reaction Rate

The rate of reaction is the change in the amount of a reactant or product per unit time. Reaction rates are therefore determined by measuring the time ...

Measuring Reaction Rates

Polarimetry finds application in chemical kinetics to measure the concentration and reaction kinetics of optically active substances during a chemical ...

Concentration and Rate Law

The rate of a reaction is affected by the concentrations of reactants. Rate laws (differential rate laws) or rate equations are mathematical expressions ...

Determining Order of Reaction

Rate laws describe the relationship between the rate of a chemical reaction and the concentration of its reactants. In a rate law, the rate constant k and ...

Apply scientific principles and evidence to explain how the rate of a physical or chemical change is affected when conditions are varied.

Protein Interaction Capture Methods in Cells

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